Chapter 11 Nervous Tissue

Central Nervous System, both Autonomic Nervous System, involuntary Peripheral Nervous System, voluntary

Sensory or Afferent, carrying toward Motor or Efferent, carrying away

Nerves connected to the brain are called cranial, whereas nerves connected with spinal cord are called spinal nerves

Sympathetic division and Parasympathetic division

Glial cells surround neurons and provide support for and insulation between them. Glial cells are most abundant cell type in CNS.

1) Guide the migration of young neurons and formation of synapses (junctions) between neurons2) Control the chemical environment around neurons where their most important job is "mopping up" leaked potassium ions and recapturing and recycling released neurotransmitters3) Respond to nearby nerve impulses and released neurotransmitters4) Signal each other with slow-paced intracellular calcium pulses and by releasing extracellular chemical messengers

Are defensive cells in the CNS. Their processes touch nearby neurons, monitoring their health, and when they sense that certain neurons are injured or in other trouble, the microglial cells migrate toward them.

The cells line cerebrospinal fluid-filled cavities (of the brain and the spinal cord) The beating of their cilia helps to circulate the cerebrospinal fluid that cushions the brain and spinal cordl

Have processes that form myelin sheaths around CNS nerve fibers

Schwann cells, surround all nerve fibers in the PNS and form myelin sheaths around the thicker nerve fibers

Neurons

The division of a cell nucleus into two parts (neurons can't divide)

Neurons have extreme longevity. Given good nutrition, they can function optimally for a lifetime

Axon hillock and axon;dendrites

Dendrites